Research On Drought Resistant Afforestation Techniques On Weibei Loess Plateau

The paper aimed at low afforestation survival rate and slow growth of tree because of drought and lack of rain on Weibei loess plateau,the drought resistant afforestation techniques were studied.The results showedThe soil moistureit was major factor that affect the afforestation survive and growth of Robinia pseudoacacia therefore drought resistant afforestation technical measures must be adopted in artificThe drought resistant afforestation technical measures that adopted in artificial afforestation showed the afforestation survival rate and growth of barerooted seedings of were increased by 52%and 8.7%on some difficult site types by use of afforestation technique of water storage and drip irrigation.In dipping slurry afforestation measures it is optimal method that the roots of seedling were soaked in water two days and then dipped slurry in which 2%phosphate fertilizer was added.In application of ABT No.3 rooting powder the fitting concentration was 50ppm and the optimal soaking times for root were 60 and 90 minute.The inside water of soil could be effectivly utilized by covering with film in afforestation.This ensured afforestation survival rate and offseted lack of precipitation in arid area.The fitting covering specification of ground sheeting and weed were respectively 30cm~2 and 60cm~2 in afforestation.By these the soil temperature could be increased by 10%averagely.In application of container seedling the fitting afforestation age of seedling of was two years and was one year.Before 3-4 days ahead afforestation the nursery lands should be watered,when grubbing seedling the soil moisture should be proper 18%-20%.About planting techniques the fitting afforestation time was early of March to 25 of March for usual tree species.But about 15 of April was fitting to Zanthoxylum bungeanum.and Dispyros kaki.(after the buds bulging).In depth of planting the tall seedlings like populus sp and Salix matsudana should be planted 35-40cm deeper and Robinia pseudoacacia and Acer mono.10-20cm deeper.Two-year-old barerooted seedings of conifer and one-year-old container seedlings should be planted 2-3cm deeper.The fitting tree species for stem cutting afforestation were Robinia pseudoacacia,Acer mono,Prunus davidiana and Prunus armeniaca L.var.ansu which all possessed strong reproductive power from stools.The height of cutting was 20cm.The fitting specification of container seedling of Pinus tabulaeformis was two-year-old,25cm high and 0.5cm wide at basal diameter.It was one-year-old,20-28cm high and 0.3-0.33cm wide at basal diameter for seedlings of Plalycladus orientalis.For seedlings of Robinia pseudoacacia and Prunus armeniaca L.var.ansu it was one-year-old,110-120cm high and 1.1-1.2cm wide at basal diameter.For seedling of Amorpha fruticosa L.it was 60cm high and 0.5cm wide at basal diameter.The application of mycorrhiza agent showed great effect on afforestation survival rate of container seedling of Pinus tabulaeformis but no remarkable effect to Platycladus orientalis.The seeds were mixed or coated with mycorrhiza preparation and then they were used to raise seedling.Its afforestation effect was better than using mycorrhiza preparation while afforestation.